Sheldon: I'm glad we're finally getting to do something together. Just the two of us.
Mary Cooper: Sure. One thing you really miss when you're on vacation is laundry.

Mary Cooper: The trick to pancakes is bacon grease. I cook everything in it.
Leonard: Everything? Aren't you worried about your health?
Mary Cooper: Oh, doctors are always changing their minds. One week bacon grease is bad for you. The next week we're not getting enough of it.

Mary Cooper: Oh, this one's sweet. You know, for your rosary rattlers.
Leonard: Mrs Cooper, we say Catholics, not rosary rattlers.
Mary Cooper: My goodness. It's a wonder you people in California can talk at all.

Sheldon: Does this mean you're not going to sing Soft Kitty?
Mary: No, I will always sing you Soft Kitty. [sings] Soft kitty, warm kitty, little ball of fur…
Leonard: [opens door] Mrs. Cooper, were we supposed to take that pie out of the oven?
Sheldon: Get out!
Mary: Well, that was rude.
Sheldon: Well, I know, but he means well. Sing.
Mary: [sings] Happy kitty, sleepy kitty…
Sheldon: What are you trying to pull, Mom? From the top.
Mary: [to God] This is what I'm talking about. [sings] Soft kitty, warm kitty, little ball of fur…

Sheldon: There's a lot of harm in trying something new. That's why we test out drugs and cosmetics on bunny rabbits.

Leonard: Kung Fu letters might not be politically correct.
Mary Cooper: Oh, I thought the one we couldn't say was Ching-Chong.
Leonard: Yeah, that too.